The present invention relates to data input devices and, in particular, it concerns a multifunctional keypad implemented on a touch screen.
Alphanumeric data entry methods for compact electronic devices pose various problems. Mechanical keypads are one of the most popular methods, but they suffer from large space consumption that in many cases is not practical in compact mobile environments. One solution to the compactness problem is to use a mechanical multifunctional keypad. Several such solutions have been suggested, for example:
U.S. Pat. No. 4,029,915xe2x80x94S. Ojima, xe2x80x9cMiniaturized calculator keyboard switch assembly having universally pivoted key actuatorsxe2x80x9d
U.S. Pat. No. 5,852,414 S. H. Yu, D. H. Yu xe2x80x9c4-way triangle shaped alphanumeric keypadxe2x80x9d
U.S. Pat. No. 5,528,235xe2x80x94E. Lin and W. Lin xe2x80x9cmulti-status multi-function data processing key and key arrayxe2x80x9d
U.S. Pat. No. 5,861,823 G. J. Strauch and P. Samola, Data entry device having multifunction keys.
Another group of solutions that has gained popularity lately in PDA device is the use of a touch screen. Entering alphanumeric text using a touch screen is done either by hand writing recognition or using small keypads referred to in some literature as a xe2x80x9csoft keypadxe2x80x9d.
The data entry, in both cases, is done with the aid of stylus since the tip of the finger cannot give the required accuracy.
Hand writing recognition suffers from high rate of errors that reduce drastically the speed of typing and the convenience of operation. A soft keypad on a PDA screen of typical size suffers from a very small footprint for each key, which requires considerable user concentration and hence degrades the speed and comfort of use. In both cases, the user needs to employ a stylus for data entry. This is inconvenient, particularly in cases where frequent entry of short memos or the like, where the stylus must be retrieved frequently from its storage position.
There is therefore a need for a compact multifunction keypad which would not require great precision of use and which could be conveniently and effectively operated by use of the finger.
The present invention is a multifunctional keypad implemented using a touch screen, and a corresponding method for operating a keypad.
According to the teachings of the present invention there is provided, a multifunction keypad comprising: (a) a touch-sensitive surface having defined thereon a plurality of regions designated as keys; and (b) a processor associated with the touch-sensitive surface and configured to: (i) identify a contact location at which an object comes into contact with the touch-sensitive surface, (ii) determine a selected one of the keys corresponding to the one of the regions within which the contact location is located, (iii) identify a direction of motion of the object across the touch-sensitive surface relative to the contact location, and (iv) select in a manner conditional upon at least the direction of motion one of a plurality of functions associated with the selected key.
According to a further feature of the present invention, the touch-sensitive surface is a touch-sensitive display screen.
According to a further feature of the present invention, the processor is configured to select a first of the plurality of functions if the direction of motion falls within a first range of angles and a second of the plurality of functions if the direction of motion falls within a second range of angles non-overlapping with the first range of angles.
According to a further feature of the present invention, the processor is configured not to select any of the plurality of functions if the direction of motion falls within a third range of angles interposed between the first range of angles and the second range of angles.
According to a further feature of the present invention, the first range of angles is greater than the second range of angles.
According to a further feature of the present invention, the processor is further configured to determine a length of motion of the object across the touch-sensitive surface relative to the contact location.
According to a further feature of the present invention, the processor is configured to select a first of the plurality of functions if the length of motion falls within a first range of lengths in a given direction and a second of the plurality of functions if the length of motion falls within a second range of lengths in the given direction.
According to a further feature of the present invention, the processor identifies a length of motion below a given value as a touch-and-release condition.
According to a further feature of the present invention, the processor is configured not to select any of the plurality of functions on occurrence of a touch-and-release condition.
According to a further feature of the present invention, the processor is configured to select a first of the plurality of functions if the direction of motion falls within a first range of angles, and wherein the processor is configured to select the first function additionally on occurrence of a touch-and-release condition.
According to a further feature of the present invention, one of the plurality of functions is selected by the processor exclusively on occurrence of a touch-and-release condition.
According to a further feature of the present invention, a plurality of the keys provide at least four direct functions per key.
According to a further feature of the present invention, a majority of the keys provide exactly four direct functions per key.
According to a further feature of the present invention, the processor is selectively operable in a single-function mode wherein the processor selects a single function on contact with a given one of the keys independent of the direction of motion.
There is also provided according to the teachings of the present invention, a method for designating functions on a multifunction keypad defined by a plurality of regions on a touch-sensitive surface, each region being designated as a key, the method comprising: (a) identifying a contact location at which an object comes into contact with the touch-sensitive surface, (b) determining a selected key corresponding to the region within which the contact location is located, (c) identifying a direction of motion of the object across the touch-sensitive surface relative to the contact location, and (d) selecting in a manner conditional upon at least the direction of motion one of a plurality of functions associated with the selected key.
There is also provided according to the teachings of the present invention, a keypad comprising a twelve-key telephone-type alphanumeric keypad, wherein each key is a multifunction key configured for single-contact selection of one of four functions, and wherein each key corresponding to a digit in the range 2-9 is associated with three letters, and wherein the letter xe2x80x9csxe2x80x9d is associate with a key corresponding to xe2x80x9c*xe2x80x9d and the letter xe2x80x9czxe2x80x9d is associated with a key corresponding to xe2x80x9c#xe2x80x9d.
According to a further feature of the present invention, the letters xe2x80x9csxe2x80x9d and xe2x80x9czxe2x80x9d are selected by contact with the key corresponding to xe2x80x9c*xe2x80x9d and xe2x80x9c#xe2x80x9d, respectively, in conjunction with a generally upward movement.
According to a further feature of the present invention, the plurality of keys further includes a row of keys associated with at least the functions ENTER, SPACE and DELETE.
There is also provided according to the teachings of the present invention, a multifunction keypad comprising: (a) a touch-sensitive surface having defined thereon a plurality of regions designated as keys; and (b) a processor associated with the touch-sensitive surface and configured to: (i) identify a contact location at which an object comes into contact with the touch-sensitive surface, (ii) determine a selected one of the keys corresponding to the one of the regions within which the contact location is located, (iii) identify a path of motion of the object across the touch-sensitive surface relative to the contact location, and (iv) select, in a manner conditional upon at least one parameter of the path of motion, one of a plurality of functions associated with the selected key.